制作放两个小图片的按钮 - 回复 "xhui" 的问题-优快云博客

本文介绍了一种使用Delphi创建自定义按钮控件的方法。该控件能够在按钮上显示不同的图像，并通过重写WM_PAINT消息实现了绘制过程。此外，还提供了一个简单的测试代码示例来演示如何使用这个自定义的按钮。

问题来源: http://www.cnblogs.com/del/archive/2009/03/12/1409708.html#1475240

本例效果图:

自定义的类(TMyButton):

unit Unit2;

interface

uses
  Windows, Messages, Classes, Graphics, StdCtrls;

type
  TMyButton = class(TButton)
  private
    FBit1,FBit2: TBitmap;
  protected
    procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure Click; override;
  end;

implementation

{ TMyButton }

procedure TMyButton.Click;
begin
  inherited;
  MessageBox(0, 'MyButton', 'Hi', MB_OK);
end;

constructor TMyButton.Create(AOwner: TComponent);
var
  wh: Integer;
begin
  inherited;
  FBit1 := TBitmap.Create;
  FBit2 := TBitmap.Create;
  //在此可以载入图片, 为了测试方便, 我随便画两个矩形吧
  wh := Height - 8;
  FBit1.SetSize(wh, wh);
  FBit2.SetSize(wh, wh);
  FBit1.Canvas.Brush.Color := clRed;
  FBit1.Canvas.Rectangle(0, 0, wh, wh);
  FBit2.Canvas.Brush.Color := clLime;
  FBit2.Canvas.Rectangle(0, 0, wh, wh);
end;

destructor TMyButton.Destroy;
begin
  FBit1.Free;
  FBit2.Free;
  inherited;
end;

procedure TMyButton.WMPaint(var Message: TWMPaint);
var
  cvs: TCanvas;
  DC: HDC;
begin
  Inherited;
  DC := GetDC(Handle);
  cvs := TCanvas.Create;
  cvs.Handle := DC;
  cvs.Draw(4, (Height - FBit2.Height) div 2, FBit1);
  cvs.Draw(Width - FBit2.Width - 4, (Height - FBit2.Height) div 2, FBit2);
  cvs.Free;
  ReleaseDC(Handle, DC);
end;

end.

测试代码:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses Unit2;

procedure TForm1.Button1Click(Sender: TObject);
begin
  with TMyButton.Create(Self) do begin
    Parent := Self;
    Left := Random(Self.ClientWidth - Width);
    Top := Random(Self.ClientHeight - Height);
  end;
end;

end.